See also: the Boustrophedon cellular decomposition for robotic 2D coverage path planning, e.g. for mowing, painting, vacuuming, etc. The method works by decomposing an arbitrary environment into a union of smaller, simplified shapes that are easy to cover with a boustrophedon motion - moving back and forth like an ox plowing.

http://planning.cs.uiuc.edu/node352.html